The royal couple's oldest child, four-year-old Prince George, doesn't appear in the photos.
The second photo shows Louis being cradled and kissed by his older sister, Princess Charlotte.
Although Prince George wasn't featured in the two new images, captured by the Duchess of Cambridge at home in Kensington Palace, you might have missed the small detail that linked Prince George to the pictures all the same. She is wearing a navy blue cardigan by royal favourite Fina Ejerique which her brother George wore for a Vanity Fair family portrait celebrating his great-grandmother the Queen's 90th birthday.
On April 23, Prince William and Middleton welcomed the newest addition to their family. "She won't leave baby Louis' side". Charlotte has previously worn another of George's cardigans, while he once wore a pair of shorts and a shirt first worn by his father Prince William in 1984.
Now two weeks old, Prince Louis, whose full name is Louis Arthur Charles, is fifth in the line of succession to the British throne behind his grandfather Prince Charles, his dad Prince William, and his two older siblings. "She's taking her big sister duties very seriously", another palace source shared with Us Weekly.
"Charlotte is really enjoying having a younger brother to play with", a royal insider told Us Weekly. "They have a great bond, and a similar connection is growing between Charlotte and Louis", the source continued. Fortunately, for the most part she doesn't seem to mind. In the snap, Her Majesty posed with her grandkids.
"A lot of Charlotte's toys are hand-me-downs from George".
She's known to reuse her own outfits.